1. Field of the Invention
The present invention relates to a method of attaching an optical waveguide component to a printed circuit board. More particularly, the present invention is directed to a method of attaching an optical waveguide component to a printed circuit board, which enables improved flatness and precise alignment of the optical waveguide component without chemical or thermal damage to the optical waveguide component upon attaching.
2. Description of the Prior Art
As well known to those skilled in the art, when components are electrically connected with each other, or power voltage or ground voltage is supplied in large-scaled devices such as a computer, an electric signal is conventionally applied through conductive copper patterns laminated on a printed circuit board to form at least one electric circuit on an inner and outer layer of the printed circuit board. Meanwhile, nowadays, there is a need for a broad bandwidth and a high-speed signal processing in order to cope with an increased data traffic and transmission according to a rapid increase of use of the Internet and improved service on the Internet. However, the electric signal is subject to a restriction attributable to electro magnetic susceptibility (EMS) during a high speed switching within a giga band, and thus an optically interfacing medium is inevitably required.
To solve this problem, efforts have been made to develop an electro-optical circuit board (EOCB), in which both an electric signal and an optical signal are propagated in such a way that an ultra high-speed data communication is interfaced with the optical signal, and a data storage and a signal processing are conducted with the electric signal in the component on one substrate. For this, an optical waveguide and a glass plate are embedded in the printed circuit board with a copper layer patterned in a predetermined manner.
In this regard, U.S. Pat. Pub. No. 2002-51599 discloses an optical-electrical wiring board comprising an electrical wiring board having a through-hole formed therein and an optical wiring layer laminated on said electrical wiring board and including a core through which the light is propagated and a clad surrounding said core. However, this patent is disadvantageous in that the optical wiring layer is directly formed on the backside of the electrical wiring board, which makes the application to a multilayer printed circuit board difficult, and thus lowering optically interfacing properties.
Meanwhile, in manufacturing the EOCB, an initial setting is important because a wiring and an array on an outer layer of the printed circuit board depend on the attachment position of the optical waveguide component to the printed circuit board.
Furthermore, since a polymer employable for an optical waveguide component is different from a material constituting the printed circuit board, the delamination and air voids may occur at an interface between the optical waveguide component and the printed circuit board.
In the light of the above, there still remains a need to develop a method of to improve the bondability and the alignment of the optical waveguide component to the printed circuit board to lessen the loss of an optical signal transmitted to a via hole.